Customer service is the new marketing.
If you're not saying 'Hell Yeah' about something, say 'No'.
In the end, it's about what you want to be, not what you want to have.
The purpose of money is to trade for things that make you happy. So if you can bypass money and get directly to the happy, you've saved a lot of trouble. And it makes others happier, too, when you organize your business around non-monetary things.
The most important lesson is probably to spend less than you earn.
If it's not a hit, switch.